WJEC AS Physics - Unit 2.7 and 2.&

Photoelectric effect

Work function

Electron volt

Ionisation

Ionisation energy

An experiment based on the photoelectric effect demonstrates light behaves like what?

Particles that light can be demonstrated to behave as due to the photoelectric effect

What light behaves as

Demonstrating the photoelectric effect

Observing the photoelectric effect

Energy of light is directly proportional to

What the minimum energy for emission of electrons suggests

Minimum energy that must be overcome in order to eject electrons

Units of the work function

Equation for energy of light of a photon

Formula for maximum kinetic energy of ejected electrons

Vacuum photocell

What occurs in the vacuum photocell experiment

In the vacuum photocell experiment, light of a known frequency / wavelength is shone onto a photosensitive cathode, causing electrons to be rejected from the cathode. This creates what?

In the vacuum photocell (photoelectric effect)  experiment, once a current is created in the circuit, what happens?

During the vacuum photocell (photoelectric effect) experiment, the voltage increasing means what?

During the vacuum photocell (photoelectric effect) experiment, eventually when the voltage is raised high enough, what happens?

During the photoelectric effect experiment, eventually when the voltage is raised high enough, what happens?

During the photoelectric effect experiment, once no electrons reach the collector and there is zero current, the voltage is at what?

During the photoelectric effect experiment, as electrons near the collector when the voltage source is at the stopping voltage, what happens?

Method for photoelectric effect using a vacuum photocell

What KE max is equal to

How Planck’s constant can be found

Threshold frequency

Energy levels of the atom are given by

What an electron must do to move up an energy level

What an electron must do to move down an energy level

Energy of the photon absorbed or emitted for an electron to move between states must be equal to

What all EM waves consist of

What both the magnetic and electric fields oscillate to

What wavelength of light is equal to

When EM waves are emitted

How EM waves are emitted

Excitation

Why energy is needed for an electron inside an atom to move from an inner to outer shell

Why excitation energy is always less than the ionisation energy of the atom

What electrons in an atom can absorb

What happens when an electron in an atom absorbs a photon

When an electron in an atom can only absorb a photon

What the atomic electron is after excitation occurs

Why the atomic electron is unstable after excitation occurs

How vacancies in the lower shells of an atom get filled

What happens when de-excitation occurs

What de-excitation happening indirectly causes

Why atomic gases have line spectra

On an atomic level, what do atomic systems have their ow

Formula for energy levels of an atom or ion with only one electron

Stimulated emission

Population inversion

Pumping

What LASER stands for

When stimulated emission occurs

What stimulated emission does

Properties of photons produced by stimulated emission

Process required for lasers

Why population inversion needs to occur for lasers to work

2-state laser system

3-level laser system

4-level laser system

Why 2 level laser systems don’t normally exist

What happens to electrons in a 3-level laser system

What happens to electrons when they decay tepidly

What very strongly pumped means

Which levels do very few electrons sit on in a 4 level laser system

What a laser consists of

Amplifying medium of a laser

What are the 2 mirrors used for

Efficiency of laser

Semiconductor lasers

Uses of lasers

Uses of semiconductor lasers

Explain the advantage of a four-level laser system over a three-level laser system

Explain stimulated emission